Create packages for obfs4proxy for bridge administrators.

Once I complete legacy/trac#12606 (moved) and tag a release, it would probably ease deployment if there were binary packages of obfs4proxy so that bridge administrators could easily deploy obfs4 bridges (or obfs3 for that matter).

As it stands right now, the only OS I can easily make packages for is Arch Linux, but I assume "it's in AUR" won't be helpful to the vast majority of bridges out there (which I assume run some flavor of Debian).

The "correct" Debian way to package go binaries apparently involves having packages for all the dependencies.

• go.net: https://packages.debian.org/sid/devel/golang-go.net-dev
• go.crypto: https://packages.debian.org/sid/golang-go.crypto-dev
• goptlib: https://packages.debian.org/sid/golang-goptlib-dev
• siphash: NEEDS PACKAGING
• ed25519: NEEDS PACKAGING

For reference: https://wiki.debian.org/MichaelStapelberg/GoPackaging